By Perry Bacon Jr.,

URBANDALE, Iowa — In Washington, it’s all about the economy. But not here.

As the Republican presidential candidates gear up for Saturday’s critical straw poll in Ames, they are aggressively targeting a network of pastors, parents who home-school their children, evangelicals and other conservatives who care as much about stopping gay marriage as they do about the debt ceiling.

Whoever gains traction with this crucial constituency in Iowa could not only win the straw poll but could galvanize religious conservatives throughout the country who remain a powerful force in Republican politics. On Thursday night, GOP contenders squared off at a debate in Ames, hoping to more sharply define their candidacies.

In 2007, with no other major candidate rallying the Christian conservative movement, former Arkansas governor Mike Huckabee came from behind to finish second in the straw poll. He then won the Iowa caucuses and several other primary contests by courting religious conservatives.

This time, that voting bloc has more options. Former senator Rick Santorum (Pa.) is a home-schooling parent. Rep. Michele Bachmann (Minn.) has spoken about when she “gave my heart to Jesus Christ” as a 16-year-old. Former Minnesota governor Tim Pawlenty speaks openly about his shift from Catholicism to evangelical Protestantism. Rep. Ron Paul (Tex.) is eyeing the sizable group of Huckabee backers who are strongly affiliated with the tea party movement.

And conservatives across the nation are closely watching Texas Gov. Rick Perry, an evangelical who held a massive prayer rally in Houston last week and plans to announce his candidacy Saturday. His name is not on the straw poll ballot, but his supporters are waging a write-in campaign.

“There’s not the convergence this time,” said Chuck Hurley, a 2008 Huckabee backer who runs the Iowa Family Policy Center. Hurley, who has not yet decided who his favorite candidate is, added, “My friends are all over the place.”

Winning over these voters could catapult a fledgling campaign. Huckabee had little money in 2008, but he had energetic volunteers who made up for his fundraising gap. They organized supporters and even created campaign literature.

The former Huckabee backers say they are concerned about the growing budget deficit and President Obama’s economic policies, like Republicans all over the country. Many support the aims of the tea party, and some consider themselves part of it.

But these one-time Huckabee voters are social conservatives who say a candidate must have a consistent record of limiting abortion and opposing gay marriage to get their support. Some are strongly critical of former Massachusetts governor Mitt Romney, who in the past has suggested that he supports abortion rights.

Many are highly religious. In the 2008 Iowa caucuses, only 19 percent of voters who considered themselves “born again” or “evangelical” backed Romney, compared with 46 percent who supported Huckabee, according to entrance polling of caucus-goers by the National Election Pool.

“I’m an absolute fiscal and social conservative. You cannot be a fiscal conservative if you are not a social conservative,” said Julie Roe, who lives in rural Hardin County and organized for Huckabee in 2008.

The candidates spend most of their public time in Iowa giving speeches that focus on the economy and the fiscal debate in Washington. But there’s a quieter campaign underway to recruit key activists who helped Huckabee win.

Roe, who had never really engaged in politics before the 2008 campaign, got involved with Huckabee through fellow home-schooling families and connections at her church. Roe, who now sends her children to a private Christian school, says she has received calls from two candidates. She declined to say which ones.

Last week, she heard from a familiar voice: Sarah Huckabee Sanders, the former Arkansas governor’s daughter, who is helping to run Pawlenty’s Iowa operation.

Michael Farris, chairman of the Virginia-based Home School Legal Defense Association, said he has received calls from nearly every candidate and Huckabee Sanders even though he doesn’t live in Iowa and can’t vote in the straw poll. He has close ties to the thousands of parents who home-school their children in the state, and his organization’s endorsement on the eve of the 2007 straw poll helped Huckabee.

“It’s unlikely we are going to do anything this time,” before the straw poll, Farris said. “The situation is not as clear to us, with Rick Perry being the biggest issue.”

Mike Huckabee, who earlier this year ruled out a second presidential bid, has avoided endorsing a candidate. While his daughter is with Pawlenty, several of his key aides are with Bachmann.

Alice Stewart, who was Huckabee’s national press secretary and is now in the same role for Bachmann, said her candidate was making a special effort to reach key pastors in the state, just as Huckabee did four years ago.

“She acts out her faith every day, and she naturally speaks their language,” Stewart said. “Michele and the governor [Huckabee] share the natural constituency of the faith community.”

While lacking the formal training of a pastor like Huckabee, Bachmann has appeared in Iowa churches and spoken in detail about religion’s role in her life.

“See suffering that comes into your life as opportunity, really something that God brilliantly designs as a challenge to not only buffet you but also to strengthen you,” she told a crowd at New Life Community Church in Marion, Iowa, last month in a “testimony of faith” that was recorded by Radio Iowa.

Two miles from the Bachmann headquarters just outside Des Moines, Huckabee Sanders is crafting the strategy for Pawlenty.

When she first joined the campaign, Huckabee Sanders appeared in a video message, released by the campaign, which quoted her saying, “Governor Pawlenty has the same conservative convictions and executive experience I admire in my dad.”

But she played down the impact of her joining Pawlenty’s team, arguing that the Minnesota governor’s intense stumping in towns around the state and the campaign’s get-out-the-vote operation were the true keys.